Zoological Society. 47 



ruptured. From the situation of the eyes low down in the face, the 

 optic nerves are necessarily of unusual length. 



The dissections, of which I have thus briefly given the results, I 

 need hardly remark were made chiefly under water, and with the aid 

 of the microscope. 



To return to the subject which led to the inquiry, atz. the subter- 

 raneous eyeless Fauna brought to light by the Danish naturahst, you 

 in your letter briefly advert to the speculations which this curious 

 discovery gives rise to, as, " whether these animals originally had 

 eyes, and have lost them from want of use by inhabiting for ages 

 dark caves ; or, whether they were originally created without eyes, 

 for those abodes where they have no occasion for them," &c. Allow 

 me to ask — fully appreciating the difficulty of solvuig such pro- 

 blems — whether the preceding observations on the eyes of the Mole 

 are not rather in favour of the latter than of the former solution .' It 

 is easy to imagine how the optic nerve and the more important parts 

 of the organ of vision might diminish in size from little use ; but it 

 is difficult to suppose that the same circumstance could have any 

 material eff'ect in obliterating a cavity in bone — the eye's orbit — and, 

 if the Mole's eyes were thus originally designed, why may not the 

 eyeless animals have been formed in the first instance without eyes ? 

 Do not we see throughout Nature the most perfect harmony between 

 the organic structure and the modes of life and habits of the living 

 beings, so that the one is the true index of the other, — and that in 

 the most minute details ? Excuse my touching on these sjieculative 

 questions, which, probably, from their nature, always must be specu- 

 lative, — unless indeed the eyeless species are found otherwise identical 

 with species possessing eyes, and there be found also a gradation in 

 them, as to power and size in accordance with the degrees of hght to 

 which the individuals have been habituated, as in advancing from the 

 open air and the entrance of the dark abodes to their deepest recesses. 

 Also, excuse me if the matter of this letter should not be new to you. 

 Lesketh How, Ambleside, April 28, 1851. 



P.S. — It may be deserving of mention, that notwithstanding the 

 small size of the eye of the Mole, its appearance in foetal development 

 is early : thus, in a foetus which I have recently examined, the length 

 of which was about three-quarters of an inch, the eyes were distinct ; 

 they were visible — conspicuous in the naked face, even without the 

 aid of a magnifying glass, and indeed were jiot much smaller than 

 those of the adult, and but httle different in appearance : the diameter 

 of each was about yto*^ o^ ^^ inch. 



2. Notice of two Viverrid^e from Ceylon, lately living 

 IN the Gardens. By J. E. Gray, Esq., F.R.S. etc. 



The specimens here noticed were brought from Ceylon by Alex. 

 Grace, Esq., and hved some time in the Gardens of the Society. 



The first is the species which I described some years ago imder the 

 name oi Herpestes Smithii (Mag. Nat. Hist. 183/, ii.), from a speci- 

 men which was living in the Surrey Zoological Gardens, now pre- 



